Selon TERMIUM il y a cette difference (avec abatement = tax credit)

DEF – A credit that is deducted
from the income tax that an
individual or corporation would
otherwise pay. Source

OBS – It differs from a tax
deduction, which is subtracted
from a person's or a corporation's
total income, thus lowering the
taxable income against which
income tax is levied. The value of
the tax deduction for an individual
depends on the level of income.
The higher the income, the higher
the top marginal rate of tax, and
the greater the value of the tax
deduction. In the case of a tax
credit, however, the value is the
same to all recipients, since it is
deducted from the actual tax they
would otherwise pay. The tax
credit is considered a preferable
way of extending benefits to
individuals since it gives all
recipients the same amount of
money, while a tax deduction
gives a greater benefit to people
with high incomes. Moreover, a
tax credit can be paid to people
whose income is too low to
require them to pay taxes, under
a system of negative income tax,
whereas a tax deduction can only
benefit people who have taxable
income.


dividend tax credit DEF – A tax incentive to encourage Canadians to invest in Canadian corporations.
Shareholders, in their tax returns,
add together their dividends from
Canadian corporations, gross this
income up by 50 per cent,
calculate the federal tax, then
deduct a federal tax credit equal
to 75 per cent of the gross-up.
This results in a lower tax rate on
dividend income for Canadian
taxpayers who invest in Canadian
shares.